Comparisons were made of the tissue water relations, stomatal conductance and growth of grand fir (Abies grandis), white fir (Abies concolor) and their hybrids growing in a western Oregon plantation. The grand fir were naturally-regenerated trees native to the study site. White fir and hybrids were the progeny of controlled...
This study describes the soils, vegetation and age structure
of the Pinus contorta forests of Crater Lake National Park. Growth
rates of P. contorta, and levels of infection and impact of dwarf
mistletoe (Arceuthobium americanu1r) on growth of P. contorta
individuals are compared among communities.
Vegetation description is based on...
I studied the water relations traits, twig conductivity, C'3 isotopic composition,
and wood density of three conifer and five angiosperm species in western Oregon. This
study took place from spring 2002 to fall 2003 on four sites. Species were selected to
represent the diversity of drought tolerance of woody plants...
Drought resistance among genotypes of Port-Orford-cedar (Chamaecyparis lawsoniana (A. Murr.) Pan., Cupressaceae) seedlings was evaluated both in the field and in the greenhouse. Field water potentials (Ψ) of 5-year-old seedlings were measured at two high-elevation plantation sites where summer drought occurs. Measurements of Ψ were compared to survival two years...
Corydalis aquae-gelidae is a large herbaceous perennial
in the Fumariaceae that has high habitat specificity. It is
endemic to the western Cascade Range of Oregon and
Washington, almost entirely on the Mt. Hood and Gifford
Pinchot National Forests. It is a federal C2 candidate
under the Endangered Species Act and...
The dynamics of stands in the mid-elevation old-growth
Douglas-fir (Pseudotsuga menziesii) forests of the central western
Oregon Cascade Range were investigated using stand structure
analysis. Trees with different growth rates were commonly present
in the same stand, which resulted often in a weak correlation
between tree diameter and age. Thus,...
The effects of burial by tephra (volcanic aerial ejecta) on
forest understory plants were examined northeast of Mount St. Helens,
Washington, in the area where the 18 May 1980 eruption deposited
tephra but did not destroy canopy trees. At six sites along a tephra
depth gradient from 2-15 cm, understory...